PB2025: CULTURAL DATA TO NEW CLASSIFICATION OF MYELODYSPLASTIC NEOPLASIA
Authors: Tamar Saralidze, Tamar Svanidze, Irma Mamatsashvili, Marina Noniashvili
Journal: HemaSphere (2023)

Topic: 10. Myelodysplastic syndromes - Clinical Background: Myelodysplastic neoplasms (MDS) is a heterogeneous group of clonal disorders characterized by refractory anemia, bi- or pancytopenia, dismyelopoiesis, chromosomal anomalies in most cases and transformation in acute leukemia in 30-40% of cases. Pathogenesis, diagnosis, prognosis and appropriate treatment of MDS continues to be challenging problem. Aims: Our aim was to study characteristic features of hemopoiesis in vitro for each type of MDS according to 2022 WHO classification. Methods: We observed 45 patients with MDS (38 were studied retrospectively), 1 was 21, 1-41, 42 were from 60 to 90, 1 was 1year-old child. 27 women, 18 men. In all patients was researched blood and/or bone marrow leukocyte culture by the method of T. Shvelidze, Saralidze (GeoPatent 2136, 1290), that helps to reveal proliferative clone of malignant cells, that can be studied by cytochemistry and immunochemistry analyses. High amount of macrophage-lymphocyte rosettes (MLRos) formation in vitro points to the autoimmune processes in the pathogenesis of disease. In 37 patients was done cytogenetic investigations. Results: MDS with defining genetic abnormalities - MDS with low blasts and isolated 5q deletion (MDS-5q) was revealed in 4 patients (9%). In other patients was revealed morphologically defined MDS. MDS with low blasts (MDS-LB) was revealed in 15 patients (33%), among them 7 had refractory anemia, 5 -pancytopenia, 3- anemia and thrombocytopenia. MDS, hypoplastic (MDS-h) was revealed in 6 patients (13%). All of them had pancytopenia. MDS with increased blasts (MDS-IB) MDS-IB1 had 12 patients (27%), 8 had pancytopenia, 4- refractory anemia. MDS-IB2 had 7 patients with pancytopenia (16%). 1 had childhood MDS with low blasts and pancytopenia. In the last case, in all patients with MDS-IB2, in 3 patients with MDS-5q, in 8 patients with MDS-IB1 and in 7 patients with MDS-LB was revealed active proliferation of blast cells before clinical onset of acute myeloid leukemia (58 %). In the rest 4 patients with MDS-IB1, 1patient with MDS-5q, 6 patients with MDS-h and 4 with MDS-LB was revealed low proliferative activity of blast cells (blasts constituted 7-15% of cells in culture smears) (33% of total number). These patients developed clinical onset of MDS-IB1, so they did not need active chemotherapy. The rest 4 patients (9%) had MDS-LB throughout their life, they were on transfusion therapy. In 70% of patients was revealed immune conflict in the pathogenesis of MDS according to high indices of MLRos, that showed necessity of immunosuppressive therapy. Summary/Conclusion: Use of culture method enables to reveal impending appearance of excess of blasts or development of acute leukemia determining its variant. Cultural data revealed massive proliferation of blast cells 1-2 month earlier before appearing excess of blasts in bone marrow and peripheral blood, that helped to make precise diagnose and predict development of impending AML. High indices of MLRos formation in vitro pointed to the presence of immune conflict in the pathogenesis of the disease and the necessity of the immunosuppressive therapy.Electron photomicrograph. Intercellular area of blast cells filled with collagen fibers. Transverse section. 9-day-culture of bone marrow aspirate of the 1-year patient with Childhood MDS with low blasts a month earlier before manifestation of ALL. X 6000. Keywords: Hematopoiesis, Myelodysplastic syndrome